1. Field of Invention
This invention relates generally to pneumatic & hydraulic rotating cylinder apparatus and an improved method of manufacture of same. More specifically, this invention relates to high speed rotating cylinders with a broad range of applications that can operate in hostile environments virtually free from seizures.
2. Prior Art
A variety of high speed rotating cylinders exist and are used on many different type of machine tools as clamps that turn with the work piece. To achieve high speed operation many complex and costly systems have been produced. Most, due to very tightly toleranced clearances, can not allow any condensation or contaminants in their supply lines thus requiring precision filtering (5 micron required on air or hydraulic fluid supply) and high maintenance costs. Some, such as U.S. Pat. No. 6,257,122—Clamping cylinder—Michler (Heinz Dieter Schunk GMBH) 2001 and U.S. Pat. No. 4,621,568—Rotary hydraulic cylinder—Gailey (SP Manufacturing Corp.) 1986, have utilized expensive and time consuming coatings such as an aluminum oxide hard coating that is Teflon impregnated, or high purity hard surface chrome plating, trying to avoid the typical wear to aluminum cases and the inevitable seizures that follow.